It's fasttttt. I only had a quick go with it but it loaded very fast and loaded web pages faster than firefox. The preferences could do with being more straight forward and customizable but then again it is a lightweight browser.
Youtube worked perfectly with it. Very fast and loaded up straight away.
I didn't test it with multiple tabs or multiple flash.
Seems like a very promising browser. Would like to see some ad-blocking integrated with it or customizable scripts to allow it.
I was using the latest version in the hardy repositories? And the whatever webkit it decided to install with it.